>> Does anybody know sesitive assay system to detect beta-galactosidase
>> activity in cell extracts after DNA transfection (lipofectin method).
>>I believe there may be a fluorescent substrate for bgal. Detection of this
>can be made at very low levels - i think (please correct me)
>
The reagent you are after is methylumbelliferyl galactoside (MUG). After the beta-
galactosidase reaction, the product detected is methylumbelliferone, which can be
easily measured in a fluorimeter. We find about ten-fold increased sensitivity over
the ONPG method.
Michael Kertesz